So here's something for all you non-believers in the higher bypass pressure, and what you also need to consider. In another thread, several years ago, ZeeOSix posted a delta-P chart that showed 12gpm@200*F is 5 psid. Now, I'm no mechanical engineer, but when ALL of the available oil filters spec max flow rates at 8-10GPM, and we are dealing with an oil pump that we KNOW flows at least 12GPM at 5K rpm, and has another 1500RPM to go to redline, riddle me this: What, pray tell, happens to delta-P as the oil flow rate of the oil pump starts to exceed the flow rate of the filter and media?? Sure sounds like a prime candidate for delta-P to spike!
If flow is 1GPM@600RPM, and nearly 12GPM@5000RPM, we can extrapolate that the flow at 6,500RPM is >15 GPM, which far exceeds the flow ratings of these filters (Fram doesn't seem to publish max GPM ratings of its filters/media?). This is at a minimum 50% and possibly 90% higher than the rating of the Wix filters (even the XP) so pray tell, do you still think an 8-11psi bypass is going to stay shut when exposed to these conditions? Even if the oil is hot, ZeeOSix's PSID chart shows the filter will be at a minimum, 7.5PSID across the media. I'm not going to trust my engine to likely less than 0.5# of spring pressure between it and unfiltered oil. Just sayin'.
If flow is 1GPM@600RPM, and nearly 12GPM@5000RPM, we can extrapolate that the flow at 6,500RPM is >15 GPM, which far exceeds the flow ratings of these filters (Fram doesn't seem to publish max GPM ratings of its filters/media?). This is at a minimum 50% and possibly 90% higher than the rating of the Wix filters (even the XP) so pray tell, do you still think an 8-11psi bypass is going to stay shut when exposed to these conditions? Even if the oil is hot, ZeeOSix's PSID chart shows the filter will be at a minimum, 7.5PSID across the media. I'm not going to trust my engine to likely less than 0.5# of spring pressure between it and unfiltered oil. Just sayin'.